Opportunity and its twin rover, Spirit, which arrived the same month, both carrying a suite of scientific instruments to study the terrain, operated on opposite sides of the planet. Occasionally, they can balloon into regional storms in a matter of days, and sometimes even expand until they envelop the planet. The last Martian dust storm occurred in 2007.
A tropical storm watch and flash flood watch remain in effect . The minimum pressure is 1006 mb. Alberto is the first major storm of the 2018 hurricane season, which runs through the fall and often brings heavy storm damage to the Gulf Coast and southeastern United States.